My Potterton Profile 50e when started from cold works normally for about 15 minutes. Then it starts cycling 3 minutes on, 5 minutes off, 3 minutes on etc. even though the water has not reached temperature. Eventually, the water does get hot but it takes a very long time. It makes no difference if CH or HW or both are selected.

I drained the system and desludged it and also replaced the motorised valves but did not help. I read somewhere on the internet that it is probably due to a faulty flue fan but from what I can hear, it comes on normally and stays on until the bioler cycles off.

Any suggestions?

Paul, February 2008

Thanks guys. I got inpatient and called in a repair man. He says the boiler is fine but the problem is probably due to still sludge in some of the radiators. I'm gonna take them off and flush them out next week.

Paul, February 2008

do you have a roomstat fitted

steve, February 2008

is the pump working fully ?
what is the boiler stat set to ?

hi-spec plumbing & heating, February 2008